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Aberration‐free images observed with TEM and STEM
Author(s) -
Shimizu R.
Publication year - 2003
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1493
Subject(s) - optics , microscope , electron microscope , scanning transmission electron microscopy , transmission electron microscopy , low voltage electron microscope , spherical aberration , contrast transfer function , phase (matter) , electron tomography , materials science , physics , quantum mechanics , lens (geology)
A defocus image modulation processing (DIMP) technique was verified successfully with the JSPS (Japan Society for the Promotion of Science) Super Electron Microscope that was developed in a 5‐year (1996–2001) project called ‘Development of Super Electron Microscope in Next Generation’ under the JSPS Research for the Future programme (RFTF). This novel DIMP‐transmission electron microscope (DIMP‐TEM) is commercially available as the first phase‐contrast electron microscope. The DIMP‐TEM enables aberration‐free images of the selected phase contrast or amplitude contrast to be observed on cathode ray tubes in real time (2/30 s), leading to dynamic observation of events such as migration of a single atom on a surface as well as unstained biological specimens, where a low phase contrast is an inherent part of their images. The situation regarding scanning transmission electron microscopes (STEMs) is more favourable from a technical point of view, although this has yet to be recognized. According to the reciprocity theorem, any aberration‐free imaging technique for TEMs should be, in principle, applicable to STEMs. A DIMP‐STEM would enable us to extract aberration‐free scan images observed with an ideal electron probe and obtained by an aberration‐free electron optical system. This paper reviews recent advances in DIMP‐TEMs and presents a proposal for a novel DIMP‐STEM. Copyright © 2003 John Wiley & Sons, Ltd.